Fire alarm actuator



Feb. 26, 1957 w, JOHNSON 2,782,746

FIRE ALARM ACTUATGR Filed Jan. 18, 1954 3 Sheets-Sheet l Walter H.Johnson INVENTOR.

Feb. 26, 1957 w. H. JOHNSON 2,782,746

FIRE ALARM ACTUATOR Filed Jan. 18, 1954 3 SheetsSheet 2 Wa/fei H.Johhsan IN VEN TOR.

Feb. 26, 1957 w. H. JOHNSON 3 FIRE ALARM ACTUATOR Filed Jan. 18, 1954 sSheets-Sheet s War/fer H. Johnsoh IN V EN TOR.

FIRE ALARM ACTUATOR Walter H. Johnson, Tacoma, Wash.

Application January 18, 1954, Serial No. 404,521

12 Claims.- (Cl. 116101) This invention relates to a fire alarm actuatorand more particularly to a device which contains a supply of gas underpressure or a liquid which gas or liquid will be released when thepressure thereof exceeds a predetermined amount.

An object of this invention is to provide a fire alarm actuatorcomprising a container having a resilient portion which is distended andsevered when the pressure of gas in the container is increased due to anincrease of temperature surrounding the container.

Another object of this invention is to provide a fire alarm actuatorwherein the effectiveness of the actuator is not reduced due to the ageof the device.

A further object of this invention is to provide a fire alarm which willhave a prolonged period of actuation.

A still further object of this invention is to provide a fire alarmactuator which is simple and cfiicient in construction and durable andlasting in use.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

Figure l is an exploded perspective view of one form of fire alarmforming the subject of this invention;

Figure 2 is a side elevational view with parts shown in section of theform of fire alarm illustrated in Figure 1;

Figure 3 is a perspective view of the severing means used in connectionwith the fire alarm of Figure 1;

Figure 4 is an exploded perspective view of a modified fire alarmactuator forming the subject of this invention; V

Figure 5 is a perspective view showing the modified fire alarm actuatorof Figure 4 in assembled position;

Figure 6 is a sectional view taken substantially along section line 66of Figure 5;

Figure 7 is a sectional view showing the fire alarm actuator of Figure 4mounted for use with a bell type fire alarm;

Figure 8 is a top plan view showing the fire alarm actuator of Figure 4mounted for use with a switch in an electrical fire alarm circuit;

Figure 9 is a sectional view taken substantially along the section line9--9 of Figure 8.

Referring now more particularly to the accompanying drawings it Will beseen that the improved fire alarm illustrated in Figure 1, includes acontainer 10 having an outlet 12 secured thereto. The container 10 maybe of metal or any other suitable material and is filled with a gaswhich is non-inflammable and non-poisonous.

The outlet 12 is internally threaded as at 14. Disposed within theoutlet 12 is an externally threaded portion 16 having a diaphragm ofresilient material 18 secured thereto. The diaphragm 18 is adapted toseal the outlet 12. Secured in the outlet 12 above the diaphragm 18 isan externally threaded bushing 20. The bushing 20 extends beyond the endof the outlet 12. The bushing 20 is provided with a wire cage 22extending upwardly therefrom. The wire cage 22 is shaped in a conesimilar to the expected shape of the diaphragm 18 when the diaphragm isdistended due to an increase in pressure of the gas within the container10. The members of the wire cage 22 are provided with knife-like edgesfacing the diaphragm 18. The configuration of these members can be moreclearly seen in Figure 6.

An adaptor 24 is provided with an internally threaded end 26 forengagement on the portion of bushing 20 which extends beyond the end ofoutlet 12. The other end of the adaptor 24 is externally threaded as at28. A whistle comprising a cylindrical housing 30 closed at both endsand having an inlet 32 secured to the housing 30 mid-way of its length.The outer end of the inlet 32 is provided with an internally threadedportion 34 which engages the threaded portion 28 on adaptor 24. Thehousing 30 is provided with a notch 36 adjacent the connection of theinlet 32 to the housing 30. The notch 36 extends completely through thewall of the housing 30.

A transverse slot 38 is provided at each end of the housing 30 andextends through the wall of the housing. A reed 40 is mounted within thehousing 30 overlying each of the slots 38.

In practical use of the device shown in Figure 1, the device isassembled and placed in a convenient position within a building. In theevent that fire breaks out in the building the temperature surroundingthe container 10 will be increased which will cause the gas within thecontainer 10 to expand. The diaphragm 18 will be distended until itengages the wire cage 22 and further expansion of the gas within thecontainer 10 will cause the wire cage 22 to sever the diaphragm 18. Whenthe diaphragm 18 is severed the gas within the container will be allowedto pass through the adaptor 24 and inlet 32 into the housing 30. Theinitial gas being under extreme pressure will cause the reeds 40 to sealagainst the slots 38. The gas will be allowed to escape through notch 36causing a whistling sound. As the pressure of the gas declines thewhistle will become less effective but will be supplemented by theactuation of the reeds which will operate at the decreased pressure.Therefore, the combination of the notch 36 and the reeds 40 will providemeans whereby the effectiveness of the signal will be prolonged.

Figures 4, 5 and 6 illustrate a form of actuator to be used inconjunction with various type of fire alarm systems. In this embodiment,a container 42 is formed of a resilient material and filled with anon-inflammable and non-poisonous gas or liquid. A collapsible wire cageis provided for severing the container 42 when the container isdistended due to an increase of pressure within the container caused byan increase of the temperature surrounding the container.

The wire cage shown in Figures 4 to 6 is formed of a lower section 44and an upper section 46 which will move together when the container 42is collapsed. The section 44 is formed of a circular base member 48having a plurality of longitudinally extending members 50 extendingupwardly and outwardly therefrom. The upper ends of members 59 areconnected together by a ring 52. The length of members 50 is such thatwhen the base 42; engages one end of the cylinder 42 the ring 52 will bedisposed substantially mid-way along the container 42.

The upper section 46 is formed of a top member 54 having a plurality ofdownwardly and outwardly extending longitudinal members 5'6 securedthereto. The lower end of the members 56 extend radially outwardly as at58. When the lower section 44 and the upper section 46 are disposedabout the container 42 the radially outwardly extending ends 58 ofmembers 56 will engage the lower surface of the ring 52 for retainingthe sections in position on the container 42. When the container 42 iscollapsed the upper section 46 will be free to move within the lowersection 44.

The members 50 and 56 are provided with inwardly facing knife edges 60,as shown in Figure 6. As the container 42 is distended to the increaseof pressure within the container the knife edges 60 will sever thecontainer to allow the gas therein to escape whereby the container 42will collapse.

The container 42 is provided with outwardly extending projections 62 ateach end thereof. The base 48 is provided with a central aperture 64 forreceiving one of the projections 62 and the top member 54 is providedwith an aperture 66 for receiving the other projection 62. By theengagement of the projection 62 in the apertures 64 and 66 the container42 will be centrally positioned within the wire cage.

Figures 7, 8 and 9 show the actuator of Figures 4, and 6 used inconnection with various fire alarm systems. In the system illustrated inFigure 7 there is provided a mounting plate 68. Bolts '70 extend fromthe mounting plate 68 and are adapted to receive on their other ends aplate similar to plate 68 and spaced parallel thereto. Secured to theplate 68 adjacent one end is a shaft 72. Parallel to shaft 72 and spacedtherefrom is a shaft 74 mounted for rotation on the plate 68. A coilspring 76 is wound about the shaft 74 and fixedly secured at one end tothe shaft 74 and secured at its other end to shaft 72. Also secured tothe shaft 74 for rotation therewith is a large gear 78. A shaft 80rotatably mounted on the plate 68 supports a gear 82 for meshingengagement with the gear 78. The gear 82 is fixedly secured to the shaft80 for rotation therewith.

Secured to the shaft 80 i a crank arm 84 having a pin 86 extending fromone side thereof. A clapper 88 is pivotally mounted intermediate itsends on a shaft 90 secured to the plate 68. One end of the clapper 88 isprovided with a longitudinally extending slot 92 which receives the pin86 on crank arm 84. Thus, when the spring 76 is tensioned and releasedgear 78 will drive gear 82 which in turn will drive shaft 80 and crankarm 84 to cause the pin 86 to oscillate clapper 88 about the pivot 90.

The other end of clapper 90 is provided with a mallet 94 which strikes abell 96 mounted on a pin 98 secured to a covering 100 which extendsbetween the mounting plate 68 and the plate spaced parallel thereto.

One side of the covering 100 is provided with a longitudinal slot 102through which the clapper 88 extends. Extending between the mountingplate 68 and its parallel plate is a platform 104 positioned below theclapper 88 and between the pivot 90 and the slot 102. The actuatorillustrated in Figures 4, 5 and 6 is adapted to be mounted in a verticalposition on the platform 104 and engaging the clapper 88 to retain thesame in its uppermost position.

In practical use of the device illustrated in Figure 7 when the spring76 is tensioned and the actuator is placed on the platform in engagementwith the clapper 88 the actuator will restrict the movement of theclapper. However, when the container 42 has been severed and the section46 moves within the section 44 the clapper 88 will be released wherebythe spring will drive gears 78 causing the mallet 94 to strike the bell96. This operation will continue until the spring 76 has run down.

In the embodiment shown in Figures 8 and 9 there is disclosed anelectrical circuit for a fire alarm system. A switch plate 106 isprovided which has a horizontal portion 108 spaced vertically from andparallel to a horizontal portion 110. Pivotally mounted at one end ofportion 108 are a pair of switch arms 112. The portion 108 is providedwith a recess 114 into which an end of arms 112 extend and pins 116extend through the recesses 114 and through the arms 112 for providing apivot for the arms 112.

s The arms 112 are interconnected by a plate 118. The

4 plate 118 is formed of insulated material and is positioned on thearms 112 at a point overlying portion 110. A leaf spring 120 is fastenedat one end to portion 108 by fasteners 122 and has the other end thereofoverlying the upper surface of plate 118. The leaf spring 120 will urgethe arms 112 toward the portion 110. Electrical conductors 124 areconnected to the end of portion 108. Screws 126 secure the conductors124 to the portion 108. Spring clips 128 are connected to the screws 126and overlie the ends of the arms 112 for providing an electricalconnection between the conductors 124 and the arms 112.

Electrical conductors 130 are connected at one end to the end of portionopposite the portion 108. Extening upwardly from the connection ofconductors 130 to the plate 110 are contacts 132. The contacts 132 arepositionsd so as to be engaged by the ends of arms 112 when the arms 112are urged downwardly by the spring The actuator of Figures 4, 5 and 6 isadapted to be positioned in vertical relation on the portion 110 andengaging the plate 118. When the container 42 is completely filled theactuator will maintain the arms 112 out of contact with the contacts132. However, when the gas has been released from container 42 the aircage will collapse allowing the spring to urge the arms 112 into contactwith the contacts 132. This will close the circuit between theconductors 124 and and cause the fire alarm signal to be actuated.

The conductors 130 may be connected to a suitable source of electricityand conductors 124 may be connected to a suitable fire alarm signal. Theswitch plate 106 is formed of insulating material so that theelectricity cannot pass therethrough from conductor 124 to conductor 130unless the switch is closed.

From the foregoing, the construction and operation of the device will bereadily understood and further explanation is believed to beunnecessary. However, since numerous modifications and change willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction shown and described, andaccordingly, all suitable modifications and equivalents may be resortedto, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. A fire alarm actuator comprising a container adapted to be filledwith a supply of gas under pressure, said container having a resilientportion adapted to be distended due to an increase of pressure of thegas within the container and means mounted adjacent said portion forsevering said portion to release said gas when said portion is distendeda predetermined amount.

2. The combination of claim 1 wherein said means comprises a wire cagesurrounding said resilient portion, said wire cage being provided withknife-like edges facing said resilient portion.

3. A fire alarm comprising a container adapted to be filled with asupply of gas under pressure, said container having an outlet therefrom,a flexible diaphragm mounted in said outlet for closing the same, aconduit connecting said outlet to a signal device, means mounted in saidconduit above said diaphragm to sever said diahragm when the diaphragmis distended due to an increase of pressure of the gas within thecontainer whereby said gas will be released to activate said signalmeans.

4. The combination of claim 3 wherein said means comprises a wire cagemounted in said conduit and overlying said diaphragm, said cage beingprovided with knife-like edges facing said diaphragm.

5. A fire alarm comprising a signal device, means for actuating saidsignal'device, said means including a container having a supply of gasunder pressure, said container having a resilient portion adapted to bedistended by an increase of pressure, of the gas within the containerand means mounted adjacent said portion for severing said portion torelease said gas when said portion is distended to a predeterminedamount whereby said signal device will be operated.

6. The combination of claim 5 wherein said signal means comprises awhistle, a. conduit connecting said whistle to said container, adiaphragm in said conduit sealing the same and means in said conduit forsevering said diaphragm when said diaphragm is distended due to anincrease in pressure of the gas in the container whereby said gas passesthrough the conduit to the whistle to actuate the same.

7. The combination of claim 5 wherein said signal device, includes abell, a clapper for said bell, drive means for actuating said clapper,said container being formed of a body of resilient material, saidreleasing means comprising a collapsible wire cage surrounding saidcontainer, said cage being provided with knife-like edges facing saidcontainer whereby said container will be severed by said cage when thecontainer is distended due to an increase in pressure of the gas in thecontainer, said cage and container engaging said clapper to preventmovement of the clapper when the container is full, said Wire cagecollapsing when the gas is released from said container to allow saidclapper to be actuated to strike the bell.

8. The combination of claim 5 wherein said signal device includes aplurality of electrical conductors, switch means disposed between saidelectrical conductors, spring means urging said switch means to a closedposition, said container being formed of a body of resilient material,said releasing means comprising .a collapsible wire cage surroundingsaid container, said cage being provided with knife-like edges facingsaid container whereby said container will be severed by said cage whenthe container is distended due to an increase in pressure of the gas inthe container, said cage and said container engaging said switch meansto maintain the switch in open position when the container is full, saidcage collapsing when the gas is released from said container to allowsaid spring to urge said switch means to closed position.

9. The combination of claim 3 wherein said signal means includes alongitudinal cylinder closed at both ends, said conduit being connectedto said cylinder midway of its length, said cylinder having a notchtherein adjacent the connection of said conduit thereto, said cylinderbeing provided with a transverse slot adjacent each end thereof andextending therethrough, and a reed mounted in said cylinder andoverlying said slots.

10. A fire alarm actuator comprising a resilient container having asupply of gas under pressure therein, a wire cage surrounding saidcontainer, said cage being formed of upper and lower sections, saidlower section being formed of a base member a plurality of upwardly andoutwardly extending longitudinal members secured to said base member, aring member connected to the upper ends of said longitudinal members,said upper section being provided with a top member, a plurality ofdownwardly and outwardly extending longitudinal members secured to saidtop member, the lower ends of said longitudinal members extendingradially outwardly, said upper and lower sections adapted to bepositioned over the container with the radially outwardly extendingportions of the upper longitudinal members engaging the lower surface ofsaid ring member.

11. The combination of claim 10 wherein said longitudinal members on theupper .and lower sections are provided with knife-like edges facing thecontainer whereby the container will be severed by the members when thecontainer is distended due to an increase in pressure of the gas withinthe container.

12. The combination of claim 11 wherein said container is provided witha projection extending from each end thereof, said base member and saidtop member being each provided with a central aperture for the receptionof said projections whereby said container will be centrally positionedwithin said cage,

References Cited in the file of this patent UNITED STATES PATENTS1,984,140 Kohlndorfer Dec. 11, 1934 2,483,657 Messick Oct. 4, 19492,496,687 Amprim Feb. 7, 1950 2,530,051 Ferguson Nov. 14, 1950 FOREIGNPATENTS 373,304 Great Britain May 26, 1932

